Basell and Shell Chemicals are advancing plans for a Basell buyout of Shell's interest in their 50-50 ethylene joint venture-Soci??t?? du Craqueur de l'Aubette-in Berre, France. As part of the deal, Basell will purchase Shell's butadiene business in Berre and take over logistics operations in Aubette, Berre, and Fos. Basell says the deal allows it to fully back-integrate its polyethylene and polypropylene plants in Berre and a polyethylene plant in Fos.